On account of the problems which often appeared in the biomass pyrolysis device, a new set of improved biomass pyrolysis device was designed. It contains four parts: feed system, fluidized bed, cyclone separation system and condenser system. It has mainly solved the problems through the improved equipment as below: blind arch phenomenon in feed bucket, feed pipe jammed and the feed system leakage; when it makes pyrolysis experiment, the sand grains are easy to be carried out of the fluidized bed ; the cyclone separator separation efficiency is low; the condensation speed is slow and so on.